Monday, November 12, 2007

Black-capped and Carolina Chickadees: A Day for the Birds


Any day that I see an adult bald eagle flying directly over a Susquehanna River bridge as I’m crossing said bridge on my way to work has to be a day when my blog is dedicated to birds. Sorry, there’s no photo of the eagle. It’s a blessing I didn’t crash the car. Still, the sighting is a great way to start a rainy Monday, or any Monday, or heck, even a Friday.

See the two chickadees in today’s photo? It’s not as good a photo as I would like, nor does it show all the important field marks, but in my opinion it does show a Carolina (top) chickadee and a black-capped chickadee (bottom). Two of the field marks that this photo does show pretty well are the differences in the bibs—the bottom edge on the Carolina is neat versus the black-capped's ragged bottom edge. And to some extent you can see the white wing edging on the black-capped versus minimal white wing edging on the Carolina. The bird on the wire is also smaller than the other, though because it is also a bit closer, that doesn't show up as well. There's also very slight differences in color, and the black-capped's tail is very slightly longer than that of the Carolina's. I'm also tempted to call the cap on the black-capped as extending further down the head/neck, but because of the angle at which the Carolina is perched, that might be a bit deceptive.

The bird activity at my feeders is starting to pick up, and I’m already getting a sense of who are going to be regular visitors this year. The numbers I will report for each species represent the total number I’ve seen at one time, so it’s likely this number doesn’t represent every individual, but it represents at least the minimum number of that species. For example, I regularly have 4 blue jays that arrive together like a squadron of bomber jets, scattering smaller birds in every direction. But at some point in the day, I will have a single blue jay arrive and feed. Now is this simply a hungrier bird of one of the four who breaks formation and sneaks off to get an extra portion of food? Or is this a different blue jay that travels on its own? I don’t know. I suspect it’s blue jay #5, but I have no way to prove that, so I only report 4 blue jays, the number I’m sure of.

So, here’s what I saw this weekend at my feeders:
4 blue jays
2 white-breasted nuthatch - I only see one of these at a time but one has a cap that’s dead black and the other’s cap is a dark gray.
1 red-breasted nuthatch – This little cutie is now a regular at the feeders. So far my photos have been poor, to say the least. I hope to get at least one good photo of it before it disappears.
2 cardinals - so far. I'm pretty sure there's at least 2 pairs, but so far I've only ever seen one pair at a time.
2 goldfinch – Likely more are around but my finch feeder has only two perches and so far I’ve seen no sign of finches stacking up and waiting for an open slot.
2 juncos – This is still a low number, considering the number of juncos in the area. That tells me they are so far finding enough natural food that they don’t yet need to rely on my feeder
1 white-throated sparrow – same comment as for the junco
5 Black-capped chickadees
3 Carolina chickadees
2 Downy woodpecker (male and female)
2 Red-bellied woodpecker (male and female)
4 Tufted titmouse

4 comments:

dguzman said...

Thanks for the info on BC vs Car chickadee! I now realize I might have been mis-IDing the chicks in my yard!

Carolyn H said...

dguzman:

One thing I forgot to mention: also take a look at the difference in how far down the throat the black bib goes on the Carolina versus the black-capped.

Carolyn H.

PA-Birder said...

I would agree with your Chickadee asessment. Have you ever read anything by anyone what to look for when in comes to a hybrid, besides a mixture of the two?
Vern

Carolyn H said...

Vern: No, I've never seen anything specific about "hybrids." I'm still not convinced that a "species" that willingly interbreeds, even prefers the males of the one species and then produces viable offspring are really 2 different species. If there's any characteristics that are typical of the hybrids--as opposed to just any old mix of characteristics--I haven't heard about it. It would be interesting to find out if there are any. For instance, are the wing edgings the first thing to go? Or does the size change? The tail length, whater. Have you ever read the book The Beak of the Finch? That talks about how a species' bill size changes dramatically through natural selection in just a few years, and the selection occurs because of wet/dry years. It would be interesting to learn if the chickadees are selecting for something typical of a more southerly chickadee.

Carolyn H.